Nitrogen-potassium fertiliser

ABSTRACT

The invention relates to the production of nitrogen-potassium fertilizers and can be used for the chemical industry and for agriculture. The inventive liquid nitrogen-potassium fertilizer comprises carbamide, potassium chloride, an ammoniated component and water. Ammonium nitrate is used as the ammoniated component with the following mixing ratio of ingredients in: 20-34 mass % carbamide, 5-25 mass % potassium chloride, 25-42 mass % ammonium nitrate, the rest being water. Said liquid nitrogen-potassium fertilizer also comprises 0.3-3 mass % magnesium sulphate or 1.5-3 mass % clay.

FIELD OF ART

The invention relates to the production of nitrogen-potassiumfertilizers and can be used for the chemical industry and foragriculture.

STATE OF ART

There is a known liquid nitrogen-potassium fertilizer comprising anaqueous solution of carbamide CO(NH₂)₂ and potassium nitrite KNO₂, whichis obtained by adding carbamide to 10-70% KNO₂ solution in the amount of2-60% by total weight of the solution (SU

214551, Int. cl. C05D 1/00, 1968). The disadvantage of this fertilizeris that it comprises nitrogen in form of nitrite (N₂O₃) and amide (NH₂)only, whereas most of the plants need the fertilizers comprisingnitrogen in form of nitrate (NO₃) and ammonium (NH₄).

There is a known liquid nitrogen-potassium fertilizer, which comprisespotassium sulfite K₂SO₃ and potassium nitrite KNO₂ aqueous solution withconcentrations of 5-52 mass % and 2-60 mass %, respectively (SU

451677, Int. cl. C05D 1/00, C05C 11/00, 1974). The disadvantage of thisfertilizer is that it comprises nitrogen in form of nitrite (N₂O₃) only.

The closest to the fertilizer of this invention in composition ofnutrients is a liquid nitrogen-potassium fertilizer, which comprisescarbamide CO(NH₂)₂ aqueous solution, potassium chloride KCl and ammoniumhydroxide NH₄OH—the ammoniated component with concentrations of 15-42mass % , 1-7 mass %

0.25-2 mass %, respectively. Water concentration lies within the rangeof 30-55 mass % (US Al

3918952, 1975). The disadvantage of this fertilizer is that it comprisesrelatively small mass of nutrients, nitrogen and potassium, due to usinglarge amount of water. In this fertilizer nitrogen is present in form ofammonium (NH₄) and amide (NH₂) but it is not present in form of nitrite(N₂O₃) and nitrate (NO₃). The study carried out by the authors has shownthat this fertilizer has a freezing temperature between −(14÷26)° C. forthe range of water content of 50-30 mass %, respectively, which makes itimpossible to store the fertilizer under autumn and winter conditions inmost of the regions of Russia.

DISCLOSURE OF THE INVENTION

The technical task to be solved by this invention is increasing thenumber of nitrogen forms and the mass of nutrients in the fertilizer andreducing its freezing temperature.

The set task is solved by using in the liquid nitrogen-potassiumfertilizer comprising carbamide, potassium chloride, an ammoniatedcomponent and water, ammonium nitrate as the ammoniated component withthe following mixing ratio of ingredients in: 20-34 mass % carbamide,5-25 mass % potassium chloride, 25-42 mass % ammonium nitrate, the restbeing water. Said nitrogen-potassium fertilizer also comprises 0.3-3mass % magnesium sulphate or 1.5-3 mass % clay.

The main distinctive features characterizing the fertilizer lie in thefact that ammonium nitrate is used as the ammoniated component with thefollowing mixing ratio of ingredients in: 20-34 mass % carbamide, 5-25mass % potassium chloride, 25-42 mass % ammonium nitrate, the rest beingwater.

Additional distinctive features lie in the fact that the fertilizercomprises 0.3-3.0 mass % magnesium sulphate or 1.5-3 mass % clay. Thesaid fertilizer comprises nitrogen in three forms: in form of amide(NH₂), in form of ammonium (NH₄) and in form of nitrate (NO₃).

This invention conforms to the condition for patentability as to noveltysince in the prior art there has not been found an engineering solutionwhose essential features are in full coincidence with all featurescontained in an independent claim of the invention. The invention alsoconforms to the condition for patentability as to an inventive levelsince the prior art does not contain a description of the engineeringsolution whose distinctive features are aimed at solution of thetechnical task aimed at by this invention.

THE EMBODIMENT OF THE INVENTION

An essence of the invention is explained by terms of the followingexamples.

EXAMPLE 1

Crystalline carbamide CO(NH₂)₂ and potassium chloride KCl are graduallyadded to 25% solution of ammonium nitrate NH₄NO₃. The obtained solutionis heated up and stirred.

The resulting solution comprises 20 mass % CO(NH₂)₂, 25 mass % KCl, 25mass % NH₄NO₃, 30 mass % water H₂O. The freezing temperature of thissolution is −27.5° C., content of nutrients is as follows: 15 mass %potassium in terms of K₂O; 9.2 mass % nitrogen in form of amide NH₂; 8.5mass % nitrogen in form of ammonium NH₄ ⁺. and in form of nitrate NO₃ ⁻.The total content of nutrients is 32.7 mass %.

A comparison between the composition of the inventive fertilizer andthat of its prototype (its lower limit) comprising 15 mass % carbamide,7 mass % potassium chloride, 2 mass % ammonium hydroxide NH₄OH showsthat the fertilizer of this invention has a higher content of nutrients,32.7 mass % versus 11.9 mass % nutrients of the prototype fertilizer.Furthermore the prototype fertilizer does not contain nitrogen innitrate form, and its freezing temperature is 13.5° C. higher than thatof the inventive fertilizer.

EXAMPLE 2

Powdered potassium chloride and ammonium nitrate are added to 34%carbamide solution. The obtained solution is stirred at a roomtemperature. The resulting solution comprises 34 mass % carbamide, 5mass % potassium chloride, 42 mass % ammonium nitrate, 19 mass % water.The freezing temperature of this solution is −28° C., content ofnutrients is as follows: 15.6 mass % nitrogen in form of amide; 14.3mass % nitrogen in form of ammonium and in form of nitrate; 3 mass %potassium in terms of K₂O. The total content of nutrients is 32.9 mass%.

A comparison between the composition of the inventive fertilizer andthat of its prototype (its upper limit) comprising 42 mass % carbamide,7 mass % potassium chloride, 2 mass % ammonium hydroxide shows that theinventive fertilizer has a higher content of nutrients, 32.9 mass %versus 24.3 mass % of the prototype fertilizer. Furthermore, theprototype fertilizer does not contain nitrogen in form of nitrate, andits freezing temperature is 2° C. higher than that of the inventivefertilizer.

EXAMPLE 3

Powdered potassium chloride and ammonium nitrate are added to 27%carbamide solution. The obtained solution is stirred at a temperature of50° C. The resulting solution comprises 27 mass % carbamide, 15 mass %potassium chloride, 33 mass % ammonium nitrate, 25 mass % water. Thefreezing temperature of this solution is −30° C., content of nutrientsis as follows: 12.42 mass % nitrogen in form of amide; 11.22 mass %nitrogen in form of ammonium and nitrate; 9 mass % potassium in terms ofK₂O. The total content of nutrients is 32.64 mass %.

A comparison between the composition of the inventive fertilizer andthat of its prototype (its upper limit) comprising 42 mass % carbamide,7 mass % potassium chloride, 2 mass % ammonium hydroxide NH₄OH showsthat the inventive fertilizer has a higher content of nutrients, 32.64mass % versus 24.3 mass % of the prototype fertilizer. Furthermore, theprototype fertilizer does not comprise nitrogen in form of nitrate andcomprises rather small amount of nitrogen in form of ammonium (0.8 mass% ammonia nitrogen in form of N—NH₄ ⁺ in 2 mass % nitrogen hydroxideNH₄OH), and its freezing temperature is 4° C. higher than that of theinventive fertilizer.

EXAMPLE 4

Crystalline carbamide CO(NH₂) and potassium chloride KCl are graduallyadded to 25% solution of ammonium nitrate NH₄NO₃. The obtained solutionis heated up and stirred, while adding magnesium sulphate and clay.

The resulting solution comprises 20 mass % CO(NH₂)₂, 25 mass % KCl, 25mass % NH₄NO₃, 3 mass % MgSO₄, 1.5 mass % clay, 25.5 mass % water H₂O.The freezing temperature of this solution is −28,5° C., the content ofnutrients is same as in Example 1 and makes up in total 32.7 mass %.

A comparison between the composition of the inventive fertilizer andthat of the prototype fertilizer (its lower limit) comprising 15 mass %carbamide, 7 mass % potassium chloride, 2 mass % ammonium hydroxideNH₄OH shows that the fertilizer of this invention has a higher contentof nutrients, 32.7 mass % versus 11.9 mass % in the prototypefertilizer. Furthermore, the prototype fertilizer does not containnitrogen in form of nitrate, and its freezing temperature is 14.5° C.higher than that of the inventive fertilizer.

EXAMPLE 5

Powdered potassium chloride and ammonium nitrate are added to 34%carbamide solution. The obtained solution is stirred at a roomtemperature, while adding magnesium sulphate and clay. The resultingsolution comprises 34 mass % carbamide, 5 mass % potassium chloride, 42mass % ammonium nitrate, 0.3 mass % magnesium sulphate, 3 mass % clayand 15.7 mass % water. The freezing temperature of this solution is −29°C., the content of nutrients is as follows: 15.6 mass % nitrogen in formof amide; 14.3 mass % nitrogen in form of ammonium and nitrate; 3 mass %potassium in terms of K₂O. The total content of nutrients is 32.9 mass%.

A comparison between the composition of the inventive fertilizer andthat of the prototype fertilizer (its upper limit) comprising 42 mass %carbamide, 7 mass % potassium chloride, 2 mass % ammonium hydroxide(NH₄OH) shows that the fertilizer of this invention has a higher contentof nutrients, 32.9 mass % versus 24.3 mass % of the prototypefertilizer. Furthermore, the prototype fertilizer does not containnitrogen in form of nitrate, and its freezing temperature is 3° C.higher than that of the inventive fertilizer.

INDUSTRIAL APPLICABILTY

The liquid nitrogen-potassium fertilizer of this invention is a stablebalanced system which features valuable agrochemical properties due to ahigh content of potassium and nitrogen, being present in form of amide,ammonium and nitrate, with the total content of nutrients from 32.64 to32. mass % and the freezing temperature from −(27.5 to 30)° C. Thispermits to store the fertilizer under autumn-winter conditions in mostregions of Russia and to expand the field of its application—thefertilizer can be used for top dressing by spraying it on the leaves.

1. A liquid nitrogen-potassium fertilizer comprising carbamide,potassium chloride, ammoniated component and water, differing in thatammonium nitrate is used as the ammoniated component with the followingmixing ratio of ingredients in: 20-34 mass % carbamide, 5-25 mass %potassium chloride, 25-42 mass % ammonium nitrate, the rest being water.2. The liquid nitrogen-potassium fertilizer as claimed in claim 1,differing in that it also comprises 0.3-3 mass % magnesium sulphate. 3.The liquid nitrogen-potassium fertilizer as claimed in claim 1 differingin that it also comprises 1.5-3 mass % clay.